The increase of drug abuse has created a need for new methods of analyzing drug residues in physiological fluids that are accurate, rapid and cost effective. Most methods require large capital expenditures for equipment, are time consuming and are costly per unit test.
U.S. Pat. No. 3,915,639 issued October 1975 to Friedenberg discloses a method for dipstick identification of drugs of abuse based upon the incorporation of an ion-exchange resin in a bibulous support together with a hydrazine salt which acts as a stain intensifying agent. It is found that the preferred hydrazine, 2-4 dinitrophenyl, is not soluble in common solvents and is not functional in the manner disclosed. Applicant here uses neither the hydrazines or ion-exchange resins.